Original URL: http://www.theregister.co.uk/2012/05/02/intel_tdd_lte/
Intel chums up with Huawei for Oriental style flexible 4G push
Eastern fancy for time-duplexing not so inscrutable
Intel will set up an interoperability testing site in China, with local firm Huawei, to ensure its TD-LTE kit will work properly even if no-one seems very interested in using it.
The two companies will work together on the testing site to be focused on ensuring compatibility with the Time Division Duplex variant of the LTE standard. TDD LTE will be deployed in China for 4G telephony, and US operation Clearwire will be switching to the standard next year. It also has spectrum allocations in India, the UK and elsewhere despite overwhelming (and unfathomable) industry preference for FDD technologies.
This deal is primarily intended to get Intel chips into Chinese phones, in the radio stack if not the central processor, but is also indicative of Intel's continuing move away from the WiMAX standard it backed so heavily, and at such cost.
Intel's spending on WiMAX was justified by its patent holdings in the technology; if WiMAX had triumphed the return would have been considerable, but that battle is over and last week the chip giant spent $75m on the patent portfolio of Aware Inc to shore up its interest in LTE.
Huawei is providing TD-LTE infrastructure to India's Bharti Airtel amongst others, so compatibility with the emerging standard is worth having even if western operators remain largely wedded to the FDD version of the standard.
Frequency Division Duplexing uses separate, and equally-sized, frequency bands for sending and receiving signals. That works well for voice where the traffic is roughly equal, but for data services an asynchronous rate becomes more sensible and can be delivered using TDD which uses a single channel swapped between sending and receiving as required.
It might seem an obvious improvement - dynamically-adjusted asynchronous speeds in less-ridged blocks of spectrum at the cost of some latency (~20ms as opposed to the 12ms possible with FDD) - but the telecommunications industry is firmly locked into the idea of separate channels for sending and receiving. The UK mega-auction, still planned for later this year, will see huge amounts of radio spectrum sold off, most of it paired into FDD blocks which, given the nature of most data services, end up nearly half empty.
Network operators, and many regulators, even measure radio spectrum in paired blocks - referring to 2x15MHz rather than 30MHz or even just claiming to only own 15MHz of spectrum despite that being only half of a pair, to the confusion of outsiders.
But TDD lets companies deploy mobile data into less-structured blocks of spectrum, as demonstrated by UK Broadband. The firm is currently hawking TD-LTE networks around Southwark and Swindon, slotted into its unpaired 3.5GHz band. The UK will see 50MHz of spectrum (around 2.6GHz) reserved for TDD services, but the rest will be bundled up into pairs as preferred by the incumbent operators in a pattern replicated around the world. In that context TD-LTE could prove to be an interestingly-disruptive technology, and one which Intel will be pleased to take advantage of. ®